People may find that in the previous blogs here, one statement is often mentioned that GN is a professional manufacturer of mud system for CBM. But what is CBM? We think maybe few people know it if not involved in this line.

What is CBM

CBM or coal bed methane is a type of natural gas produced from coal. The coal seam is both the source and the reservoir, which is different from conventional oil and gas.

The Formation of CBM

During the coalification process, some organic matter is converted into coal, while some other organic matter is transformed into natural gas, which is then adsorbed onto the surface of the coal. The methane stored is up to seven times the amount of natural gas stored in a conventional sandstone reservoir.
When the pressure of the coals at depth is released, the CBM produced. This process is called dewatering, for this occurs when water trapped within the coal is removed.

How People Develop the CBM

The challenge in developing CBM is to find ‘sweet spots’that allow gas to flow at commercial rates. These factors include gas content and saturation in the coal, the permeability of the coal, thickness of the coal seams and the areal extent.
A 300 to 1,200 metre deep well is used to extract CBM from the coal bed. A special rotating blade ream out cavities in the coal seams. Water, released from the coal, is pumped from the well then the gas separate from the coal and flow into the well. The water is transported through underground pipes to a dam for possible reuse and recycling. The gas passes through a separator near the well head to remove water traces before being piped to a processing facility to be compressed and dehydrated. The gas is then fed into commercial pipelines.